Features: Replacement by the cnc machine cutting and winding, automatic line change. Manual winding is cumbersome and can easily get stuck during use, which can cause damage to the string trimmer. High-quality abs spool & durable polyamide nylon thread, flexible and long service life. Use centrifugal force and aerodynamics to reduce drag and achieve fast cutting. Twisted line for added strength and durability. High-quality abs spool and durable nylon string trimmer line,grass Trimmer edger line,sturdy enough,strong enough for long working life. Auto feed spool replacement parts for use centrifugal force and aerodynamics to reduce drag and achieve fast cutting. Specifications: Material:Plastic Size:As Picture Shown Package Includes: 6x Trimmer Replacement Spool 1x Replacement Spool Cap Cover note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thanks for your understandings.